Data from: Bottom time does not always predict prey encounter rate in Antarctic fur seals ...

• Main Authors: Viviant, Morgane, Jeanniard-Du-Dot, Tiphaine, Monestiez, Pascal, Authier, Matthieu, Guinet, Christophe, Jeanniard Dudot, Tiphaine
• Format: Dataset
• Language: English
• Published: Dryad 2017
• Subjects: Foraging depth; Antarctic fur seals; Aerobic diving limit; Diving behaviour; Arctocephalus gazella; Foraging strategies; Holocene; Antarctic; The Antarctic; Antarc*; Antarctic Fur Seal; Antarctic Fur Seals
• Online Access: https://dx.doi.org/10.5061/dryad.ct511; https://datadryad.org/stash/dataset/doi:10.5061/dryad.ct511

Optimal foraging models applied to breath-holding divers predict that diving predators should optimize the time spent foraging at the bottom of dives depending on prey encounter rate, distance to prey patch (depth) and physiological constraints. We tested this hypothesis on a free-ranging diving marine predator, the Antarctic fur seal Arctocephalus gazella, equipped with accelerometers or Hall sensors (n = 11) that recorded mouth-opening events, a proxy for prey capture attempts and thus feeding events. Over the 5896 dives analysed (>15 m depth), the mean number of mouth-opening events per dive was 1·21 ± 1·69 (mean ± SD). Overall, 82% of mouth-openings occurred at the bottom of dives. As predicted, fur seals increased their inferred foraging time at the bottom of dives with increasing patch distance (depth), irrespective of the number of mouth-openings. For dives shallower than 55 m, the mean bottom duration of dives without mouth-openings was shorter than for dives with mouth-opening events. However, ... : Fur_seal_dive_capture_dataThis file is an excel data files regrouping the complete dive data set used in this paper. each column are clearly labbelled Campain: field season; fur seal pup ID use to identify the female; female size in cm; female mass in kg; night index, form 0 (first night spent at sea, to a maximal value corresponding to the last night recorded); Dive_ID: an incremental dive number for a given female form the first dive to the last dive available for that female. Start_time_dt : date and time at the beginning of the dive,Max_Depth:_m : maximun diving depth for the corresponding dive, surf_before: time spent at surface prior to the dive; desc_time_s : duration in second of the descent phase of the dive, Bottom_time_s: duration in seconds of the bottom phase of the dive; asc_time_s: duraction in seconds of the ascent phase of the dive; depth_end_desc_m: depth in meter at the end of the decent phase of the dive; depth_start_asc_m: depth in meters at the begining of the ascent phase of the dive; ...